Episode 412, "Knuckle Up" Friday, May 24, 12|11c
SEASON 4, EPISODE 410 - After a dying convict gives Rush clues to an unsolved cop killing, she reopens the case. Born into a family of police officers, young patrolman Sean ""Coop"" Cooper (Shane Johnson) worked the streets during a time when tough, not completely legitimate methods of dealing with drug offenders were the norm. When Coop's body was found under a bridge in a bad neighborhood in 1968, the theories ranged from revenge to a gang killing to a jealous lover. But Rush's investigation uncovers a secret about Coop that may have motivated someone entirely unexpected to murder him.